Monge's Theorem

Monge’s Theorem states that when three different points are viewed from three distinct locations, the three perspectives’ "loci" (or the lines of sight from each observer) create three specific points called the "points of perspective," which are actually the centers of the circles passing through the pairs of observer positions. These three circle centers are always aligned so that they form a straight line. This geometric relationship reveals how different viewpoints of the same objects relate, highlighting a consistent and predictable pattern in the way perspectives and lines of sight behave in three-dimensional space.